The purpose of the proposed Mentored Scientist Career Development Award (K01) is to provide the candidate with mentoring and research experiences that will promote her development as an independent researcher, with particular emphasis in the field of mixed methods HIV intervention research in drug-using populations. Objectives of the training are to develop knowledge and skills in: 1) substance abuse epidemiology, assessment and prevention, to understand how intimate partner violence (IPV) affects drug-using populations and the subsequent risk for HIV/STIs; 2) theoretically-driven behavioral HIV prevention interventions; 3) mixed methods research, specifically related to HIV interventions; and 4) advanced statistics such as structural equation modeling. Training activities will include didactic coursework and specific workshops, directed readings and one-on-one tutorials with mentors, and instruction in the responsible conduct of research. The candidate will receive mentorship from a Training Committee comprised of nationally renowned experts in the fields of substance abuse, behavioral interventions, and mixed methodology research at the University of California, San Diego. The specific aims of the proposed research are to: 1) assess the effect of recent IPV and sexual relationship power differentials on the sexual risk behaviors of HIV-negative heterosexual methamphetamine (MA)-using women enrolled in the intervention arm of an HIV behavioral intervention; 2) examine whether cognitive mediators (e.g., condom use self-efficacy and outcome expectancies) mediate the relationship between recent IPV and sexual relationship power and sexual risk behaviors; and 3) qualitatively characterize how the context of IPV and sexual relationship power differentials affect the implementation of safer sex behaviors during and after participation in the HIV behavioral intervention. The research aims will be accomplished by conducting a mixed methods HIV intervention study. Quantitative data will come from an ethnically diverse sample of 100 MA-using women enrolled in the intervention group of an HIV prevention intervention study designed to reduce sexual risk behaviors, MA use, and depressive symptoms (FASTLANE2, PI: Patterson). Qualitative data will come from in-depth interviews of a subsample of 30 MA-using women enrolled in the FASTLANE2 study, reporting IPV and varying sexual relationship power differentials. Findings from the proposed research will position the candidate to propose an R34 or R01 proposal to pilot test a theoretically-driven, mixed methods behavioral HIV prevention intervention that addresses the multiplicity of risks among drug-using women in the context of female-controlled barrier methods and empowerment. Moreover, the candidate's ethnic minority background combined with the proposed training and research will support a career trajectory focused on vulnerable, underserved populations at risk for HIV while becoming an influential mentor to underrepresented women.